The present invention is concerned with a technique for diminishing blood loss during solid organ surgery.
Because of their vascularity, solid organs pose particular problems concerning blood loss during surgery which need to be approached differently from blood loss problems when carrying out other types of surgery. The most important solid organs in this connection are the liver and the spleen.
Thus, blood loss, bile leak and postoperative liver function are the main concerns for surgeons operating on the liver (1), surgical resection remaining the only potentially curative procedure for dealing with hepatic tumours. Increased intraoperative bleeding is associated with higher postoperative complication and shorter long-term survival. In addition it is a major parameter in evaluating results of liver resection since it affects postoperative morbidity, mortality and long term survival in malignant disease. Operative blood loss can occur during dissection, parenchymal transection and revascularisation. Different techniques have been developed to allow safe liver resection (4-7). Surgeons can decrease intraoperative blood loss by limiting or occluding the inflow occlusion, performing a careful and sometime time-consuming parenchymal dissection or both. Inflow occlusion can be obtained by means of Pringle manoeuvre or total vascular exclusion. Parenchymal division can be performed using the scalpel, crushing the tissue with the finger or clamps, using ultrasonic dissectors and hydrodissectors or stapling devices. Vascular and biliary structures larger than 2 mm require ligation and division. However late bleeding and bile leak are possible even if high tech devices are used and are often caused by insufficient ligation or oozing from the resection surface secondary to tearing of small vessels.
Radio-Frequency-Thermal (RFT) energy has increasingly been used to locally ablate unresectable hepatic disease (8-11). Electricity converts current into thermal energy by ionic agitation and in so doing causes proteins to denature and results in coagulative necrosis.
Insofar as the spleen is concerned, it is one of the most vascular organs in the human body. It has a fine capsule structure with a soft parenchyma which bleeds profusely when injured. When the spleen starts to bleed because of accident or iatrogenic trauma during surgery in adults, it bleeds profusely and splenectomy is usually performed to arrest bleeding and to save life.
Partial splenectomy is not practised because of poor vascular control to induce haemostasis. Likewise Tru-cut biopsy of the spleen is never performed in the work-up diagnosis for haematological malignancies and often the surgeon is asked to perform a total splenectomy to provide the pathologist with splenic tissue to reach a diagnosis.
Related disclosures are identified in a listing appended hereto and referred to by number in the foregoing passages and hereinafter.
An object of the invention is to provide a technique for diminishing blood loss during solid organ surgery.
According to the present invention, there is provided a method of reducing blood loss during solid organ surgery, wherein diseased or damaged tissue is removed from the solid organ by delivery of thermal energy to the tissue by a probe.
A probe having a cooled tip has been found to be of use, provided that it can be employed with the cooling means inactivated during the withdrawal of the probe. As a result of the procedure of this invention, the region or regions of the solid organ through which the probe has been inserted is/are sealed. To obtain this effect over a wide area of tissue a plurality of probes will be required. These will advantageously be in line, linked in the form of a comb structure.
Although the method of this invention is described particularly with reference to use of a source of radio-frequency thermal energy for removal of diseased tissue, and will be described herein generally with reference thereto, the invention is not limited to the use of such heat source. Alternatively, it is possible to use other sources of heat deliverable by a probe such as laser energy source and bipolar energy source heat generating means, provided that one obtains coagulative dissection of the resection margins which can then be divided with a surgical scalpel.
In practice, the method defined above utilising RFT energy has been shown to define the edges of solid organ resection with an at least 2 cm wide coagulative necrosis zone in surgery using a multi probe application followed by a scalpel division of the parenchyma and suture of blood vessels bigger than about 2.5 mm. The technique can also be used in liver surgery, inter alia for major liver resections including right and left hemi-hepatectomies as well as in surgery carried out on the spleen.
Insofar as this invention offers a technique to control haemostatis in the spleen the method of this invention allows a surgeon to perform either partial splenectomy or Tru-cut biopsy. As with liver surgery, the rationale for vascular control preferably uses radiofrequency heat ablation (RFA) to induce coagulative desiccation of tissue, this resulting in complete obliteration of the vessel and ensuring haemostatis.